T-square and drawing-board attachment



(No Model.) 2 Sheets-Sheet 1. A. T. PAGE. T-SQUARE AND DRAWING BOARD ATTACHMENT.

Patented May 24, 1892.

(No Model.) 2 Sheets-Sheet 2.

A. T. PAGE. T-SQUARE AND DRAWING BOARD ATTACHMENT.

No. 475,741. Patented May 24, 1892.

. if 5 w/5 g2 UNiTEn STATES PATENT OFFICE.

ARTHUR T. PAGE, or MINNEAPOLIS, MINNESOTA.

T-SQUARE AN D DRAWING-BOARD ATTACHMENT.

SPECIFICATION forming part of Letters Patent No. 475,741, dated May 24, 1892.

Application filed July 8, 1890. Serial No. 358,093. (No model.)

To all whom it may concern:

Be it known that I, ARTHUR T. PAGE, of Minneapolis, in the county of Hennepin and. State of Minnesota, have invented certain new and useful Improvements in T-Squares and Drawing-Board Attachments, of which the following is a specification.

This invention relates to improvements in T-squares and guides therefor; and the objects I have in View are to provide an improved T-square which can be readily and easily adjusted to any desired position on the drawing-board with which it is used and the blade of which can quickly be adjusted to the desired angle with the head or can be removed and used as a ruling-edge independently of the head; also, to improve the construction of the square in several particulars to produce a more convenient and durable instrument.

In the accompanying drawings, forming a part of this specification, Figure 1 is a perspective View of a drawing-board with my T-square thereon. Fig. 2 is a top view of the plate that holds the sliding guide-bar. Fig. 3 is a top View of the sliding guide-bar. Fig. 4. is a view of the counter-balance for the sliding guide-bar. Fig. 5 is an end elevation of the guide-bar. Fig. 6 is a detail section of a part of the drawing-board, grooved plate, and sliding bar. Fig. 7 is a detail of a portion of the lower edge of the drawing-board, showing the buttons for holding the drawing-board or T-square. Figs. 8 and 9 are details of portions of the head of the T-square, showing the means for clamping it to the guide-bar. Figs. 10, 11, 12, and 13 are details of portions of a T-square head and blade, the head and blade being made of wood. Figs. 14, 15, and 16 are similar details of the rubber head and blade. Fig. 17 is a view of the washer. Figs. 18, 20, and 21 are views of the T-square blade. Fig. 19 is a plan of the square, showing the blade connected to one side of the head and showing the brace connected to the head and blade. Fig. 22 is a detail of a portion of the blade, showing a slot in the end in place of a perforation. Fig. 23 is a detail of the edge of the board, showing the second set of buttons thereon.

In the drawings, 2 represents a drawingboard, which may be of any ordinary form close to either edge of the board or even beyond the edge and still be provided with a firm bearing for the head, I provide a sliding guide-bar 7, that may be drawn out beyond either edge of the board, as in Fig. 1. The

guide-bar 7 is arranged in a grooved bar 9,

that is secured across the end of the board 2. This bar may be secured to the board by any suitable means. I prefer to provide it with a plate or flange that projects under the board and has keyhole-slots 11, by which it is detachably secured upon screws 13, that are illserted in the under side of the board. This grooved bar may be applied to either edge of I the board, or similar bars may be applied to two or more edges. The bar 7 fits into the groove in the plate orbar 9 and slides freely therein. Set-screws 15 are tapped through the wall of the groove and are adapted to bear against the bar 7. The bar 7 may be removed and used as a straight-edge, if, desired,.and So the square may be used on the board Without the bar 7, as shown in Fig. 8. The upper edge of the bar 7 is preferably cut away on the inside and made thin for a purpose hereinafter set forth, and this upper edge, when the bar is in place, is flush with the surface of the board. The straightedge of the head fits against the outer surface of the bar 7 when the square is in place, and as the square is moved over the board the head slides along the edge of the bar. WVhen it is desired to use the square at the edge of the board or to bring the head beyond this edge, as shown in Fig. 1, the bar 7 is drawn out beyond the edge of the board and forms a guide and support 5 for the square.

As the drawing-board is often used on an incline, I provide means for counterbalancing the sliding bar 7, so that when the set-screws are loosened it will be held in equilibrium in too the groove and maybe easily moved in either direction therein. A cord 19 is attached to the end of the bar 7 and passes over a pulley 21 and has its end secured to the bar 9. A

The blade 3 of 55 10, 11,12, and 13.

small weight 23 is placed on the cord, as shown in Fig. 1.

The head of the T-square may be of ordinary form and size. It has preferably afriction-washer 27, secured to its upper surface in position to come between the head and the under surface of the blade. A series of radial grooves may be cut in the head to form a protractor, by which the blade may be set at any desired angle, (see Fig. 14;) or I may provide graduations upon the edge of the metallic washer and provide a spring 29' upon the blade that will bear against the edge of the washer and spring into a notch therein when the blade is at right angles to the head. This washer is preferably provided with a circular rib on its under surface that fits into the circular groove in the top of the blade. A

' plate 28 connects the Washer with the head and prevents its turning with the blade.

It is quite often desirable to use several sizes of blades with a single T-square head. I therefore provide the head of the square witha series of fine parallel lines 29 close together and at right angles to its straigh t-edge. A blade of any size may be used on thehead and the edge will coincide with one of the marks on the head.

I prefer to provide for each head a series of blades of various sizes and materials and form in each one a swivel-hole that is in the same position relatively to the end of the blade. In Fig. 20 1 have shown the blade provided with a strengthening-bar 33 secured to it. This bar serves to strengthen the blade and forms a handle by which the blade may be grasped when it is desired to raise it from the board. It often occurs that one edge of the blade will become dented or nicked after the square has been used for some time. It has been customary in such cases to turn the blade over, so as to bring its other edge into use. This, however, cannot be done with the blade having the bar on its upper side, and it is never desirable to do this, as the upper surface usually becomes soiled after the square has been used for a time, and when the blade is turned over it soils the paper. To obviate this objection, I make the blades reversible by providing them with a swivel-hole 32 at each end. W hen one edge of the blade has become uneven, I remove the blade from the head, reverse it, and swivel the other end to the head.

The means thatI use for swiveling the blade upon the head is shown particularly in Figs.

A sleeve 41, having a head upon one end, is passed through the head and blade and into a washer 4:3, placed on the blade. A screw 45 is passed through the sleeve, and a thumb-nut 47 is provided for the threaded end of the screw. A small screw 49 is set through the head of the sleeve 41 and into the head of the square. By this means the screw 45 is kept from turning and the sleeve is held in the head.

It is sometimes desirable to clamp the square to the bar 7, as when a triangle is being used with the square for section-lining. For this purpose I provide the head of the blade with a clamp consisting of a slide 71, which is held in place by a strap 73, that is secured to the head of the blade. The slide has a downwardly-projecting lip 75, that is adapted to engage with the edge of the bar 7, and an upwardly-extended opposite end provided with a set-screw 77, that bears on the strap 73. This screw may have a rubber spring-washer, if preferred. By turning up this screw and drawing the lip against the bar the square may be held in any desired position. A notch in the edge of the head receives the lip 75 when the clamp is not in use. (See Fig. 8.) A rubber friction-block 72 may be inserted in the head under the slide to keep it from moving too easily. In some instances I prefer to provide a brace-rod extending diagonallyfrom the blade to the head of the square. This rod 81 is pivoted at one end to the blade, as shown in Fig. l 9, and passes through a swiveled block or post 83 on the head. A clamping-screw 85 is provided in the post, by which the rod may be clamped after the square has been properly adjusted. The rod may be graduated and a pointer may be attached to the post for use in setting the blade at an angle to the head. This rod firmly braces the square and still allows the blade to be readily adjusted whenever desirable. I may also attach a strap or tape 91 to each end of the blade and pass them over a roller 93, mounted at the edge of the board. Light weights 95 are attached to the ends of the tapes. When the square is used on an inclined board, the Weights counterbalance the weight of the square and keep it from sliding off the board. The tapes may be used for marking off distances from either end of the blade, or theblade may be detached from the head and used with the tapes alone for parallel lining.

For the purpose of compressing the leather washer 27 after it is in place I prefer to moisten this washer and then put the blade in position, then screw the nut up, and then work the blade on its pivot back and forth, thereby solidifying the washer, so that when it becomes dry it is hard and firm and will hold any kind of blade. This washer may be moistened occasionally, especially when'used on a lines 52, extending across it and making a measure of it. To make the blades handsomer in appearance, the blade may be colored on the top surface at the ends and the top of the head around the blade may be gilded, as in- IIO The head may be longer at one dicated at 54 in Fig. 10, to improve the appearance and form a contact with the parallel lines thereon.

For the purpose of keeping the bar 7 at the point where it will most generally be used the plate 9 is provided with a spring at its end, which may be located on the under side of the plate and bear against the under side of the bar. This will create sufficient friction on the bar to keep it from moving too easily in the grooved plate. By forming a notch 62 in the bar the spring will engage this notch and retain the bar normally in this position; but by pressing thebar in either direction the end of the spring will leave the notch. I may also provide aclip or lip 64.- on the head of the T-square that projects over the edge of the bar 7, and when the square is moved up to the upper end of the bar 7 this clip will engage a notch 66 in the top of the bar, and a further movement of the square will disengage the spring 60 from the notch in the bar and cause the bar to move along in the grooved plate.

A plate 68 on the plate 9 projects over the bar 7 when it is in position and holds the bar in position in the grooved plate. The upper part of the bar 7 may also be slightly undercut, as shown in Fig. 5, so that when the square is secured thereto by the clamp it may be moved along on the bar without being capable of being lifted therefrom without further releasing the clamp. The lower edge of the board may be provided with the buttons 70, (shown in Figs. 1 and 7,) and these buttons may be turned so as to project above the broad, as indicated by dotted lines in Fig. 7. By this means the edge of the square may be brought against these buttons, and the blade may then be set at right angles to the head with precision and very quickly. For the same purpose notches 7 2 may be formed in the ends of the board, having their lower edges at right angles to the end of the board. The top of the blade may have strips of velvet 78 glued or secured thereon to hold drawing-instruments, as shown in Fig. 21.

Instead of providing the T- square with a thumb-nut, as shown, it may have a thumbscrew consisting of a head 74:, cast upon a common screw 76, as shown in Fig. 16. This screw would screw into a thread formed in the sleeve on the lower washer.

By providing the plate 9 with the inclined slots 11 the plate may be attached to various boards whether the screws 13 are located the same or not.

Instead of using the roll on the upper edge of the board I may use a roll 80 on a rod 82, projecting from the plate 9, and the tape on the square may pass over the roll, the other tape being omitted. I may also provide a second series of buttons 84: on the lower edge of the board, against which a second board 86 may rest, as indicated in Fig. 23.

I prefer to use a thin calf-skin washer between the head of the square and blade, and this washer is preferably prepared and put 011 as follows: A piece of leather is first soaked in a suitable solution, so as to extract all or nearly all of the greasy matter, and then allowed to dry. It is then cut out in the form desired for the washer and cemented to the head with thick shellac to unite the washer to the wood,which may be polished. Then when the washer becomes partly set I apply water to the top side of the washer and put on the blade and screw down the nut and then work the blade back and forth, then screw down the nut a little tighter than at first for a moment while the leather sets a little, and then loosen the nut a trifle and work the blade a little. The washer dries a little and is hard, smooth, and perfect for use and will hold the. blade almost immovable when the nut is screwed down tight, and should the washer after a time become too dry it can be moistened at any time to increase the friction; This is sometimes necessary with a rubber blade to hold it very rigid with the head.

I claim as my invention- 1. The combination, with the drawingboard, of the sliding guide-bar 7, adapted to be drawn out beyond either edge of the board, and a support for said bar extending across the end of the board, all substantially as described, and for the purpose set forth.

2. The combination, with the drawingboard, of the grooved plate 9, secured thereto, the sliding guide-bar arranged in said groove, and the set-screws adapted to secure said bar in said grooved plate, substantially as do scribed, and for the purpose set forth.

3. The combination, with the drawingboard, of the guide-bar 7, the grooved plate 9, in which said bar slides, the cord 19, attached to said bar and passing over the rolls 15, and the weight 23 on said cord, substantially as described.

4. The combinatiomwith the board and the T-square having the swivel-blade, of the sliding bar 7, adapted to be drawn out beyond either edge of the board.

5. The combination of the T-square head, with the blade, the sleeve passing through said head and blade, the pivot-screw, and the screw 49, passing through the flange of the sleeve into the head of the square, with a portion of its head fitting into a notch in the head of the pivot-screw, all substantially as described.

6. The combination,with the head and blade, of the friction-washer arranged between said head and blade, the sleeve 41, washer 4:3, screw 45, and nut 47, all substantially as described.

7. The combination, in a T-square, of the head, the blade swiveled thereto, and a friction-washer upon the swivel-screw between said head and blade, all substantially as described.

8. The combination, with the board and the sliding guide-bar 7, of the T-square, the slide 71, secured to said head and having the lip adapted to engage said bar, and the clamping-screw 7 5, for the purpose set forth.

9. The combination, with the T-square, of the sliding clamp 7l,having the downwardlyprojecting lip, the strap securing said clamp to the head of the square, and the set-screw 75, all substantially as described.

10. The combination, in a T-square, of a brace-rod pivoted to its blade, a swiveled block or post on the head, through which said rod passes, and a clamp for securing said rod to said post, substantially as described.

11. In a T-square, a head having a series of parallel lines at right angles to its straightedge and extending substantially across the head, as described, and for the purpose set forth.

12. In a T-square, the combination ofa head, a reversible blade having a swiveldiole in each end, and a round swivel securing said blade to said end, whereby the blade may be reversed and either end pivoted to the head.

13. In a T-square, the combination of a head,

a reversible blade having a bar 33 secured to its upper surface and having a round swivelhole in each end, for the purpose set forth.

14.. The combination,with the board having roll 93 extending along its edge, of the T-square blade, the tapes attached to the ends of said blade and passing over said rolls, and the weights on said tapes, for the purpose set forth.

15. The combination, with the drawingboard, of the buttons pivoted upon the lower edge of said board, as and for the purpose set forth.

16. The combination, with the guide-bar, of the plate 9, provided with the inclined keyhole-slots 11, adapted to engage the screws on the bottom of the board, substantially as de scribed.

In testimony whereof I have hereunto set my hand this 27th day of June, 1890.

ARTHUR T. PAGE. In presence of A. 0. PAUL, A. M. GAsKILL. 

